1. Field of the Invention
The present invention relates generally to computer aided design (CAD) applications and geographic information systems (GIS), and in particular, to a method, apparatus, and article of manufacture for automatically discovering hierarchical relationships in planar technologies.
2. Description of the Related Art
Computer aided design (CAD) applications are traditionally used for creating and editing drawings (e.g., maps, floor plans, and engineering designs). Further, CAD applications enable users to create/modify highly precise and accurate drawings/maps. Civil engineers and surveyors, for whom precision and accuracy are of primary importance, have adopted CAD applications to speed data input and perform computations for design projects.
Geographic information systems (GIS) have been traditionally used for spatial analysis and mapping and allow users to store, retrieve, manipulate, analyze, and display geographically referenced data. However, traditional GIS have been aimed at general cartography and broad land-use analysis, and not precision design for the construction and management of real-world projects. In this regard, the geometric precision that many engineers require has not been provided by traditional GIS systems.
Some GIS companies have attempted to use complex databases to model real-world objects. However, such databases are still built on points, lines, and polygons and cannot store geometric objects in a traditional CAD application (e.g., true arcs or road spirals). As such, use of CAD systems in a GIS environment has been limited, because the results have been less than favorable.
Many organizations have used both CAD and GIS tools in different departments to utilize the different specific features available. Further, data from original CAD drawings may be frequently imported or digitized for use in the GIS mapping environment. However, because of the limitations of GIS systems and/or CAD systems, during such a transition, data connectivity, accuracy, and geometric precision are often lost. Accordingly, what is needed is an integrated solution that provides the functionality and tools of a GIS system with the precision and accuracy of a CAD application.
In an attempt to address the above concerns, industry specific components were built on top of the CAD engine to address specialized needs and eventually, an integrated solution was developed (e.g., Autodesk Map™ software available from the assignee of the present invention). Integrated solutions attempt to provide GIS functionality (e.g., multiuser editing, polygon overlay and analysis, topology, thematic mapping, etc.) within a CAD application and spatial database. The integrated solution allows civil engineers the ability to integrate the precision engineering tasks (from CAD) (e.g., site, roadway, and hydrological design) with the spatial analysis tools and data management of GIS. Such systems are known as CAD/GIS systems.
Nonetheless, the integrated solutions may have various limitations. As such, there is a need in the art that allows for the use of precision engineering CAD programs and systems in a GIS environment.